i tried to sort dict by key but no chance. this is my dict :
result={'1':'value1','2':'value2',...}
i'm using Python2.7 and i found this
keys = result.keys()
keys.sort()
but this is not what i expected, i have an unsorted dict.
Asked
Active
Viewed 4.2k times
38
codeforester
- 34,080
- 14
- 96
- 122
Imoum
- 715
- 2
- 12
- 23
3 Answers
11
Standard Python dictionaries are inherently unordered. However, you could use collections.OrderedDict. It preserves the insertion order, so all you have to do is add the key/value pairs in the desired order:
In [4]: collections.OrderedDict(sorted(result.items()))
Out[4]: OrderedDict([('1', 'value1'), ('2', 'value2')])
NPE
- 464,258
- 100
- 912
- 987
-
1what if i had 1000 couple of (key, value) ?? – Imoum Mar 25 '13 at 12:56
-
what to do if I have to sort the `OrderedDict([('1', 'value1'), ('2', 'value2')])` in reverse order by `value*` – Chitrank Dixit Jul 08 '16 at 10:24
9
sorted(result.iteritems(), key=lambda key_value: key_value[0])
This will output sorted results, but the dictionary will remain unsorted. If you want to maintain ordering of a dictionary, use OrderedDict
Actually, if you sort by key you could skip the key=... part, because then the iterated items are sorted first by key and later by value (what NPE uses in his answer)
Jakub M.
- 30,095
- 43
- 103
- 169
-
I'd personally go for `key=lambda (key,val): val)` which is also correct, but IMHO also more explicit – Jon Clements Mar 25 '13 at 11:48
-
1@JonClements that's deprecated in python 3 so the current approach is better – jamylak Mar 25 '13 at 11:50
-
-
2
-
@JakubM. it was to do with unpacking references - the 3.x series disallowed such constructs as def f(somearg, (nextarg, otherarg)) – Jon Clements Mar 25 '13 at 11:53
-
-
3
Python dictionaries are unordered (for definition)
You can use OrderedDict instead
DonCallisto
- 28,203
- 8
- 66
- 94